214 Commits
Author SHA1 Message Date
Vasant HegdeandJoerg Roedel 1f44aab79b iommu/amd: Use maximum PPR log buffer size when SNP is enabled on Family 0x19
Due to CVE-2023-20585, the PPR log buffer must use the maximum supported
size (512K) on Genoa (Family 0x19, model >= 0x10) systems when SNP is
enabled, to mitigate a potential security vulnerability. Note that Family
0x19 models below 0x10 (Milan) do not support PPR when SNP is enabled.
Hence the PPR log size increase is only applied for model >= 0x10.
All other systems continue to use the default PPR log buffer size (8K).

Apply the errata fix by making the following changes:

- Introduce global new variable (amd_iommu_pprlog_size) to have PPR log buffer
  size. Adjust variable size for Genoa family.

- Extend 'amd_iommu_apply_erratum_snp()' to also set the PPR log buffer
  size to maximum for Family 0x19 model >= 0x10 when SNP is enabled.

- Rename PPR_* macros to make it more readable.

Link: https://www.amd.com/en/resources/product-security/bulletin/amd-sb-3016.html
Cc: Borislav Petkov <bp@alien8.de>
Cc: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Cc: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
Tested-by: Dheeraj Kumar Srivastava <dheerajkumar.srivastava@amd.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2026-04-27 13:49:36 +02:00
Vasant HegdeandJoerg Roedel 58c0ac6125 iommu/amd: Use maximum Event log buffer size when SNP is enabled on Family 0x19
Due to CVE-2023-20585, the Event log buffer must use the maximum supported
size (512K) on Milan/Genoa (Family 0x19) systems when SNP is enabled,
to mitigate a potential security vulnerability. All other systems continue to
use the default Event log buffer size (8K).

Apply the errata fix by making the following changes:

* Introduce new global variable (amd_iommu_evtlog_size) to have event log
  buffer size. Adjust variable size for family 0x19.

* Since 'iommu_snp_enable()' must be called after the core IOMMU subsystem
  is initialized, it cannot be moved to the early init stage. The SNP errata
  must also be applied after the 'iommu_snp_enable()' check. Therefore,
  'alloc_event_buffer()' and 'iommu_enable_event_buffer()' are now called
  in the IOMMU_ENABLED state, after the errata is applied.

* Adjust alloc_event_buffer() and iommu_enable_event_buffer() to handle
  all IOMMU instances.

* Also rename EVT_* macros to make it more readable.

Link: https://www.amd.com/en/resources/product-security/bulletin/amd-sb-3016.html
Cc: Borislav Petkov <bp@alien8.de>
Cc: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Cc: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
Tested-by: Dheeraj Kumar Srivastava <dheerajkumar.srivastava@amd.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2026-04-27 13:49:16 +02:00
Li RongQingandJoerg Roedel 1e0c8d6b69 iommu/amd: Add NUMA node affinity for IOMMU log buffers
Currently, PPR Log and GA logs for AMD IOMMU are allocated using
iommu_alloc_pages_sz(), which does not account for NUMA affinity. This can
lead to remote memory access latencies if the memory is allocated on a
different node than the IOMMU hardware.

Switch to iommu_alloc_pages_node_sz() to ensure that these data structures
are allocated on the same NUMA node as the IOMMU device. If the node
information is unavailable, it defaults to NUMA_NO_NODE.

Signed-off-by: Li RongQing <lirongqing@baidu.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Reviewed-by: Ankit Soni <Ankit.Soni@amd.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2026-03-17 13:26:38 +01:00
Kees CookandLinus Torvalds 189f164e57 Convert remaining multi-line kmalloc_obj/flex GFP_KERNEL uses
Conversion performed via this Coccinelle script:

  // SPDX-License-Identifier: GPL-2.0-only
  // Options: --include-headers-for-types --all-includes --include-headers --keep-comments
  virtual patch

  @gfp depends on patch && !(file in "tools") && !(file in "samples")@
  identifier ALLOC = {kmalloc_obj,kmalloc_objs,kmalloc_flex,
 		    kzalloc_obj,kzalloc_objs,kzalloc_flex,
		    kvmalloc_obj,kvmalloc_objs,kvmalloc_flex,
		    kvzalloc_obj,kvzalloc_objs,kvzalloc_flex};
  @@

  	ALLOC(...
  -		, GFP_KERNEL
  	)

  $ make coccicheck MODE=patch COCCI=gfp.cocci

Build and boot tested x86_64 with Fedora 42's GCC and Clang:

Linux version 6.19.0+ (user@host) (gcc (GCC) 15.2.1 20260123 (Red Hat 15.2.1-7), GNU ld version 2.44-12.fc42) #1 SMP PREEMPT_DYNAMIC 1970-01-01
Linux version 6.19.0+ (user@host) (clang version 20.1.8 (Fedora 20.1.8-4.fc42), LLD 20.1.8) #1 SMP PREEMPT_DYNAMIC 1970-01-01

Signed-off-by: Kees Cook <kees@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-22 08:26:33 -08:00
Linus Torvalds bf4afc53b7 Convert 'alloc_obj' family to use the new default GFP_KERNEL argument
This was done entirely with mindless brute force, using

    git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
        xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'

to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.

Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.

For the same reason the 'flex' versions will be done as a separate
conversion.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21 17:09:51 -08:00
Kees Cook 69050f8d6d treewide: Replace kmalloc with kmalloc_obj for non-scalar types
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:

Single allocations:	kmalloc(sizeof(TYPE), ...)
are replaced with:	kmalloc_obj(TYPE, ...)

Array allocations:	kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with:	kmalloc_objs(TYPE, COUNT, ...)

Flex array allocations:	kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with:	kmalloc_flex(*PTR, FAM, COUNT, ...)

(where TYPE may also be *VAR)

The resulting allocations no longer return "void *", instead returning
"TYPE *".

Signed-off-by: Kees Cook <kees@kernel.org>
2026-02-21 01:02:28 -08:00
Linus Torvalds 1e0ea4dff0 Merge tag 'iommu-updates-v7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/iommu/linux
Pull iommu updates from Joerg Roedel:
 "Core changes:
   - Rust bindings for IO-pgtable code
   - IOMMU page allocation debugging support
   - Disable ATS during PCI resets

  Intel VT-d changes:
   - Skip dev-iotlb flush for inaccessible PCIe device
   - Flush cache for PASID table before using it
   - Use right invalidation method for SVA and NESTED domains
   - Ensure atomicity in context and PASID entry updates

  AMD-Vi changes:
   - Support for nested translations
   - Other minor improvements

  ARM-SMMU-v2 changes:
   - Configure SoC-specific prefetcher settings for Qualcomm's "MDSS"

  ARM-SMMU-v3 changes:
   - Improve CMDQ locking fairness for pathetically small queue sizes
   - Remove tracking of the IAS as this is only relevant for AArch32 and
     was causing C_BAD_STE errors
   - Add device-tree support for NVIDIA's CMDQV extension
   - Allow some hitless transitions for the 'MEV' and 'EATS' STE fields
   - Don't disable ATS for nested S1-bypass nested domains
   - Additions to the kunit selftests"

* tag 'iommu-updates-v7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/iommu/linux: (54 commits)
  iommupt: Always add IOVA range to iotlb_gather in gather_range_pages()
  iommu/amd: serialize sequence allocation under concurrent TLB invalidations
  iommu/amd: Fix type of type parameter to amd_iommufd_hw_info()
  iommu/arm-smmu-v3: Do not set disable_ats unless vSTE is Translate
  iommu/arm-smmu-v3-test: Add nested s1bypass/s1dssbypass coverage
  iommu/arm-smmu-v3: Mark EATS_TRANS safe when computing the update sequence
  iommu/arm-smmu-v3: Mark STE MEV safe when computing the update sequence
  iommu/arm-smmu-v3: Add update_safe bits to fix STE update sequence
  iommu/arm-smmu-v3: Add device-tree support for CMDQV driver
  iommu/tegra241-cmdqv: Decouple driver from ACPI
  iommu/arm-smmu-qcom: Restore ACTLR settings for MDSS on sa8775p
  iommu/vt-d: Fix race condition during PASID entry replacement
  iommu/vt-d: Clear Present bit before tearing down context entry
  iommu/vt-d: Clear Present bit before tearing down PASID entry
  iommu/vt-d: Flush piotlb for SVM and Nested domain
  iommu/vt-d: Flush cache for PASID table before using it
  iommu/vt-d: Flush dev-IOTLB only when PCIe device is accessible in scalable mode
  iommu/vt-d: Skip dev-iotlb flush for inaccessible PCIe device without scalable mode
  rust: iommu: fix `srctree` link warning
  rust: iommu: fix Rust formatting
  ...
2026-02-11 16:36:08 -08:00
Ankit SoniandJoerg Roedel 9e249c4841 iommu/amd: serialize sequence allocation under concurrent TLB invalidations
With concurrent TLB invalidations, completion wait randomly gets timed out
because cmd_sem_val was incremented outside the IOMMU spinlock, allowing
CMD_COMPL_WAIT commands to be queued out of sequence and breaking the
ordering assumption in wait_on_sem().
Move the cmd_sem_val increment under iommu->lock so completion sequence
allocation is serialized with command queuing.
And remove the unnecessary return.

Fixes: d2a0cac105 ("iommu/amd: move wait_on_sem() out of spinlock")

Tested-by: Srikanth Aithal <sraithal@amd.com>
Reported-by: Srikanth Aithal <sraithal@amd.com>
Signed-off-by: Ankit Soni <Ankit.Soni@amd.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2026-02-03 14:27:05 +01:00
Sebastian Andrzej SiewiorandThomas Gleixner 5bfcdccb4d iommu/amd: Use core's primary handler and set IRQF_ONESHOT
request_threaded_irq() is invoked with a primary and a secondary handler
and no flags are passed. The primary handler is the same as
irq_default_primary_handler() so there is no need to have an identical
copy.

The lack of the IRQF_ONESHOT can be dangerous because the interrupt
source is not masked while the threaded handler is active. This means,
especially on LEVEL typed interrupt lines, the interrupt can fire again
before the threaded handler had a chance to run.

Use the default primary interrupt handler by specifying NULL and set
IRQF_ONESHOT so the interrupt source is masked until the secondary
handler is done.

Fixes: 72fe00f01f ("x86/amd-iommu: Use threaded interupt handler")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/20260128095540.863589-4-bigeasy@linutronix.de
2026-02-01 17:37:13 +01:00
Suravee SuthikulpanitandJoerg Roedel b2bb0573dd iommu/amd: Always enable GCR3TRPMode when supported.
The GCR3TRPMode feature allows the DTE[GCR3TRP] field to be configured
with GPA (instead of SPA). This simplifies the implementation, and is
a pre-requisite for nested translation support.

Therefore, always enable this feature if available.

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2026-01-18 10:56:12 +01:00
Suravee SuthikulpanitandJoerg Roedel 5335fc1657 iommu/amd: Rename DEV_DOMID_MASK to DTE_DOMID_MASK
Also change the define to use GENMASK_ULL instead.
There is no functional change.

Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2026-01-18 10:56:10 +01:00
Sairaj KodilkarandJoerg Roedel c7fe9384c8 amd/iommu: Make protection domain ID functions non-static
So that both iommu.c and init.c can utilize them. Also define a new
function 'pdom_id_destroy()' to destroy 'pdom_ids' instead of directly
calling ida functions.

Signed-off-by: Sairaj Kodilkar <sarunkod@amd.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-12-19 11:23:49 +01:00
Sairaj KodilkarandJoerg Roedel c2e8dc1222 amd/iommu: Preserve domain ids inside the kdump kernel
Currently AMD IOMMU driver does not reserve domain ids programmed in the
DTE while reusing the device table inside kdump kernel. This can cause
reallocation of these domain ids for newer domains that are created by
the kdump kernel, which can lead to potential IO_PAGE_FAULTs

Hence reserve these ids inside pdom_ids.

Fixes: 38e5f33ee3 ("iommu/amd: Reuse device table for kdump")
Signed-off-by: Sairaj Kodilkar <sarunkod@amd.com>
Reported-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-12-19 11:23:48 +01:00
Linus Torvalds 249872f53d Merge tag 'tsm-for-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/devsec/tsm
Pull PCIe Link Encryption and Device Authentication from Dan Williams:
 "New PCI infrastructure and one architecture implementation for PCIe
  link encryption establishment via platform firmware services.

  This work is the result of multiple vendors coming to consensus on
  some core infrastructure (thanks Alexey, Yilun, and Aneesh!), and
  three vendor implementations, although only one is included in this
  pull. The PCI core changes have an ack from Bjorn, the crypto/ccp/
  changes have an ack from Tom, and the iommu/amd/ changes have an ack
  from Joerg.

  PCIe link encryption is made possible by the soup of acronyms
  mentioned in the shortlog below. Link Integrity and Data Encryption
  (IDE) is a protocol for installing keys in the transmitter and
  receiver at each end of a link. That protocol is transported over Data
  Object Exchange (DOE) mailboxes using PCI configuration requests.

  The aspect that makes this a "platform firmware service" is that the
  key provisioning and protocol is coordinated through a Trusted
  Execution Envrionment (TEE) Security Manager (TSM). That is either
  firmware running in a coprocessor (AMD SEV-TIO), or quasi-hypervisor
  software (Intel TDX Connect / ARM CCA) running in a protected CPU
  mode.

  Now, the only reason to ask a TSM to run this protocol and install the
  keys rather than have a Linux driver do the same is so that later, a
  confidential VM can ask the TSM directly "can you certify this
  device?".

  That precludes host Linux from provisioning its own keys, because host
  Linux is outside the trust domain for the VM. It also turns out that
  all architectures, save for one, do not publish a mechanism for an OS
  to establish keys in the root port. So "TSM-established link
  encryption" is the only cross-architecture path for this capability
  for the foreseeable future.

  This unblocks the other arch implementations to follow in v6.20/v7.0,
  once they clear some other dependencies, and it unblocks the next
  phase of work to implement the end-to-end flow of confidential device
  assignment. The PCIe specification calls this end-to-end flow Trusted
  Execution Environment (TEE) Device Interface Security Protocol
  (TDISP).

  In the meantime, Linux gets a link encryption facility which has
  practical benefits along the same lines as memory encryption. It
  authenticates devices via certificates and may protect against
  interposer attacks trying to capture clear-text PCIe traffic.

  Summary:

   - Introduce the PCI/TSM core for the coordination of device
     authentication, link encryption and establishment (IDE), and later
     management of the device security operational states (TDISP).
     Notify the new TSM core layer of PCI device arrival and departure

   - Add a low level TSM driver for the link encryption establishment
     capabilities of the AMD SEV-TIO architecture

   - Add a library of helpers TSM drivers to use for IDE establishment
     and the DOE transport

   - Add skeleton support for 'bind' and 'guest_request' operations in
     support of TDISP"

* tag 'tsm-for-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/devsec/tsm: (23 commits)
  crypto/ccp: Fix CONFIG_PCI=n build
  virt: Fix Kconfig warning when selecting TSM without VIRT_DRIVERS
  crypto/ccp: Implement SEV-TIO PCIe IDE (phase1)
  iommu/amd: Report SEV-TIO support
  psp-sev: Assign numbers to all status codes and add new
  ccp: Make snp_reclaim_pages and __sev_do_cmd_locked public
  PCI/TSM: Add 'dsm' and 'bound' attributes for dependent functions
  PCI/TSM: Add pci_tsm_guest_req() for managing TDIs
  PCI/TSM: Add pci_tsm_bind() helper for instantiating TDIs
  PCI/IDE: Initialize an ID for all IDE streams
  PCI/IDE: Add Address Association Register setup for downstream MMIO
  resource: Introduce resource_assigned() for discerning active resources
  PCI/TSM: Drop stub for pci_tsm_doe_transfer()
  drivers/virt: Drop VIRT_DRIVERS build dependency
  PCI/TSM: Report active IDE streams
  PCI/IDE: Report available IDE streams
  PCI/IDE: Add IDE establishment helpers
  PCI: Establish document for PCI host bridge sysfs attributes
  PCI: Add PCIe Device 3 Extended Capability enumeration
  PCI/TSM: Establish Secure Sessions and Link Encryption
  ...
2025-12-06 10:15:41 -08:00
Linus Torvalds 208eed95fc Merge tag 'soc-drivers-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc
Pull SoC driver updates from Arnd Bergmann:
 "This is the first half of the driver changes:

   - A treewide interface change to the "syscore" operations for power
     management, as a preparation for future Tegra specific changes

   - Reset controller updates with added drivers for LAN969x, eic770 and
     RZ/G3S SoCs

   - Protection of system controller registers on Renesas and Google
     SoCs, to prevent trivially triggering a system crash from e.g.
     debugfs access

   - soc_device identification updates on Nvidia, Exynos and Mediatek

   - debugfs support in the ST STM32 firewall driver

   - Minor updates for SoC drivers on AMD/Xilinx, Renesas, Allwinner, TI

   - Cleanups for memory controller support on Nvidia and Renesas"

* tag 'soc-drivers-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (114 commits)
  memory: tegra186-emc: Fix missing put_bpmp
  Documentation: reset: Remove reset_controller_add_lookup()
  reset: fix BIT macro reference
  reset: rzg2l-usbphy-ctrl: Fix a NULL vs IS_ERR() bug in probe
  reset: th1520: Support reset controllers in more subsystems
  reset: th1520: Prepare for supporting multiple controllers
  dt-bindings: reset: thead,th1520-reset: Add controllers for more subsys
  dt-bindings: reset: thead,th1520-reset: Remove non-VO-subsystem resets
  reset: remove legacy reset lookup code
  clk: davinci: psc: drop unused reset lookup
  reset: rzg2l-usbphy-ctrl: Add support for RZ/G3S SoC
  reset: rzg2l-usbphy-ctrl: Add support for USB PWRRDY
  dt-bindings: reset: renesas,rzg2l-usbphy-ctrl: Document RZ/G3S support
  reset: eswin: Add eic7700 reset driver
  dt-bindings: reset: eswin: Documentation for eic7700 SoC
  reset: sparx5: add LAN969x support
  dt-bindings: reset: microchip: Add LAN969x support
  soc: rockchip: grf: Add select correct PWM implementation on RK3368
  soc/tegra: pmc: Add USB wake events for Tegra234
  amba: tegra-ahb: Fix device leak on SMMU enable
  ...
2025-12-05 17:29:04 -08:00
Alexey KardashevskiyandDan Williams eeb934137d iommu/amd: Report SEV-TIO support
The SEV-TIO switch in the AMD BIOS is reported to the OS via
the IOMMU Extended Feature 2 register (EFR2), bit 1.

Add helper to parse the bit and report the feature presence.

Signed-off-by: Alexey Kardashevskiy <aik@amd.com>
Link: https://patch.msgid.link/20251202024449.542361-4-aik@amd.com
Acked-by: Joerg Roedel <joerg.roedel@amd.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2025-12-02 12:06:45 -08:00
Thierry Reding a97fbc3ee3 syscore: Pass context data to callbacks
Several drivers can benefit from registering per-instance data along
with the syscore operations. To achieve this, move the modifiable fields
out of the syscore_ops structure and into a separate struct syscore that
can be registered with the framework. Add a void * driver data field for
drivers to store contextual data that will be passed to the syscore ops.

Acked-by: Rafael J. Wysocki (Intel) <rafael@kernel.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
2025-11-14 10:01:52 +01:00
Jinhui GuoandJoerg Roedel 75ba146c26 iommu/amd: Fix pci_segment memleak in alloc_pci_segment()
Fix a memory leak of struct amd_iommu_pci_segment in alloc_pci_segment()
when system memory (or contiguous memory) is insufficient.

Fixes: 04230c1199 ("iommu/amd: Introduce per PCI segment device table")
Fixes: eda797a277 ("iommu/amd: Introduce per PCI segment rlookup table")
Fixes: 99fc4ac3d2 ("iommu/amd: Introduce per PCI segment alias_table")
Cc: stable@vger.kernel.org
Signed-off-by: Jinhui Guo <guojinhui.liam@bytedance.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-11-13 16:15:56 +01:00
Joerg Roedel 5f4b8c03f4 Merge branches 'apple/dart', 'ti/omap', 'riscv', 'intel/vt-d' and 'amd/amd-vi' into next 2025-09-26 10:03:33 +02:00
Vasant HegdeandJoerg Roedel a0c17ed907 iommu/amd: Fix alias device DTE setting
Commit 7bea695ada restructured DTE flag handling but inadvertently changed
the alias device configuration logic. This may cause incorrect DTE settings
for certain devices.

Add alias flag check before calling set_dev_entry_from_acpi(). Also move the
device iteration loop inside the alias check to restrict execution to cases
where alias devices are present.

Fixes: 7bea695ada ("iommu/amd: Introduce struct ivhd_dte_flags to store persistent DTE flags")
Cc: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-09-13 08:11:30 +02:00
Zhen NiandJoerg Roedel 923b70581c iommu/amd: Fix ivrs_base memleak in early_amd_iommu_init()
Fix a permanent ACPI table memory leak in early_amd_iommu_init() when
CMPXCHG16B feature is not supported

Fixes: 82582f85ed ("iommu/amd: Disable AMD IOMMU if CMPXCHG16B feature is not supported")
Cc: stable@vger.kernel.org
Signed-off-by: Zhen Ni <zhen.ni@easystack.cn>
Reviewed-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Link: https://lore.kernel.org/r/20250822024915.673427-1-zhen.ni@easystack.cn
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-09-05 15:11:07 +02:00
Ashish KalraandJoerg Roedel 9be15fbfc6 iommu/amd: Skip enabling command/event buffers for kdump
After a panic if SNP is enabled in the previous kernel then the kdump
kernel boots with IOMMU SNP enforcement still enabled.

IOMMU command buffers and event buffer registers remain locked and
exclusive to the previous kernel. Attempts to enable command and event
buffers in the kdump kernel will fail, as hardware ignores writes to
the locked MMIO registers as per AMD IOMMU spec Section 2.12.2.1.

Skip enabling command buffers and event buffers for kdump boot as they
are already enabled in the previous kernel.

Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Tested-by: Sairaj Kodilkar <sarunkod@amd.com>
Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
Link: https://lore.kernel.org/r/576445eb4f168b467b0fc789079b650ca7c5b037.1756157913.git.ashish.kalra@amd.com
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-09-05 14:45:17 +02:00
Ashish KalraandJoerg Roedel 38e5f33ee3 iommu/amd: Reuse device table for kdump
After a panic if SNP is enabled in the previous kernel then the kdump
kernel boots with IOMMU SNP enforcement still enabled.

IOMMU device table register is locked and exclusive to the previous
kernel. Attempts to copy old device table from the previous kernel
fails in kdump kernel as hardware ignores writes to the locked device
table base address register as per AMD IOMMU spec Section 2.12.2.1.

This causes the IOMMU driver (OS) and the hardware to reference
different memory locations. As a result, the IOMMU hardware cannot
process the command which results in repeated "Completion-Wait loop
timed out" errors and a second kernel panic: "Kernel panic - not
syncing: timer doesn't work through Interrupt-remapped IO-APIC".

Reuse device table instead of copying device table in case of kdump
boot and remove all copying device table code.

Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Tested-by: Sairaj Kodilkar <sarunkod@amd.com>
Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
Link: https://lore.kernel.org/r/3a31036fb2f7323e6b1a1a1921ac777e9f7bdddc.1756157913.git.ashish.kalra@amd.com
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-09-05 14:44:32 +02:00
Ashish KalraandJoerg Roedel f32fe7cb01 iommu/amd: Add support to remap/unmap IOMMU buffers for kdump
After a panic if SNP is enabled in the previous kernel then the kdump
kernel boots with IOMMU SNP enforcement still enabled.

IOMMU completion wait buffers (CWBs), command buffers and event buffer
registers remain locked and exclusive to the previous kernel. Attempts
to allocate and use new buffers in the kdump kernel fail, as hardware
ignores writes to the locked MMIO registers as per AMD IOMMU spec
Section 2.12.2.1.

This results in repeated "Completion-Wait loop timed out" errors and a
second kernel panic: "Kernel panic - not syncing: timer doesn't work
through Interrupt-remapped IO-APIC"

The list of MMIO registers locked and which ignore writes after failed
SNP shutdown are mentioned in the AMD IOMMU specifications below:

Section 2.12.2.1.
https://docs.amd.com/v/u/en-US/48882_3.10_PUB

Reuse the pages of the previous kernel for completion wait buffers,
command buffers, event buffers and memremap them during kdump boot
and essentially work with an already enabled IOMMU configuration and
re-using the previous kernel’s data structures.

Reusing of command buffers and event buffers is now done for kdump boot
irrespective of SNP being enabled during kdump.

Re-use of completion wait buffers is only done when SNP is enabled as
the exclusion base register is used for the completion wait buffer
(CWB) address only when SNP is enabled.

Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Tested-by: Sairaj Kodilkar <sarunkod@amd.com>
Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
Link: https://lore.kernel.org/r/ff04b381a8fe774b175c23c1a336b28bc1396511.1756157913.git.ashish.kalra@amd.com
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-09-05 14:44:30 +02:00
Kees CookandJoerg Roedel 8503d0fcb1 iommu/amd: Avoid stack buffer overflow from kernel cmdline
While the kernel command line is considered trusted in most environments,
avoid writing 1 byte past the end of "acpiid" if the "str" argument is
maximum length.

Reported-by: Simcha Kosman <simcha.kosman@cyberark.com>
Closes: https://lore.kernel.org/all/AS8P193MB2271C4B24BCEDA31830F37AE84A52@AS8P193MB2271.EURP193.PROD.OUTLOOK.COM
Fixes: b6b26d86c6 ("iommu/amd: Add a length limitation for the ivrs_acpihid command-line parameter")
Signed-off-by: Kees Cook <kees@kernel.org>
Reviewed-by: Ankit Soni <Ankit.Soni@amd.com>
Link: https://lore.kernel.org/r/20250804154023.work.970-kees@kernel.org
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-08-15 11:50:47 +02:00